Types and construction

Chokes used in radio circuits are divided into two classes – those designed to be used with audio frequencies, and the others to be used with radio frequencies. Audio frequencycoils, usually called A.F. chokes, can have ferromagneticiron cores to increase their inductance. Chokes for higher frequencies (ferrite chokes or choke baluns) have ferrite cores. Chokes for even higher frequencies have air cores. Radio frequency coils, (R.F. chokes), usually don't have iron cores. In high power service so much heat would be produced in making and destroying the field in the core that the coil would burn up.